Myelopathy and spinal deformity: relevance of spinal alignment in planning surgical intervention for degenerative cervical myelopathy

Abnormal Static Sagittal Cervical Curvatures following Motor Vehicle Collisions: A Retrospective Case Series of 41 Patients before and after a Crash Exposure

Previous investigations have found a correlation between abnormal curvatures and a variety of patient complaints such as cervical pain and disability. However, no study has shown that loss of the cervical curve is a direct result of exposure to a motor vehicle collision (MVC). This investigation presents a retrospective consecutive case series of patients with both a pre-injury cervical lateral radiograph (CLR) and a post-injury CLR after exposure to an MVC. Computer analysis of digitized vertebral body corners on CLRs was performed to investigate the possible alterations in the geometric alignment of the sagittal cervical curve.

METHODS

Three spine clinic records were reviewed over a 2-year period, looking for patients where both an initial lateral cervical X-ray and an examination were performed prior to the patient being exposed to a MVC; afterwards, an additional exam and radiographic analysis were obtained. A total of 41 patients met the inclusion criteria. Examination records of pain intensity on numerical pain rating scores (NPRS) and neck disability index (NDI), if available, were analyzed. The CLRs were digitized and modeled in the sagittal plane using curve fitting and the least squares error approach. Radiographic variables included total cervical curve (ARA C2-C7), Chamberlain's line to horizontal (skull flexion), horizontal translation of C2 relative to C7, segmental translations (retrolisthesis and anterolisthesis), and circular modelling radii.

RESULTS

There were 15 males and 26 females with an age range of 8-65 years. Most participants were drivers (28) involved in rear-end impacts (30). The pre-injury NPRS was 2.7 while the post injury was 5.0; p < 0.001. The NDI was available on 24/41 (58.5%) patients and increased after the MVC from 15.7% to 32.8%, p < 0.001. An altered cervical curvature was identified following exposure to MVC, characterized by an increase in the mean radius of curvature (265.5 vs. 555.5, p < 0.001) and an approximate 8° reduction of lordosis from C2-C7; p < 0.001. The mid-cervical spine (C3-C5) showed the greatest curve reduction with an averaged localized mild kyphosis at these levels. Four participants (10%) developed segmental translations that were just below the threshold of instability, segmental translations < 3.5 mm.

CONCLUSIONS

The post-exposure MVC cervical curvature was characterized by an increase in radius of curvature, an approximate 8° reduction in C2-C7 lordosis, a mild kyphosis of the mid-cervical spine, and a slight increase in anterior translation of C2-C7 sagittal balance. The modelling result indicates that the post-MVC cervical sagittal alignment approximates a second-order buckling alignment, indicating a significant alteration in curve geometry. Future biomechanics experiments and clinical investigations are needed to confirm these findings.

Adult cervical spine deformity: a state-of-the-art review

Adult cervical deformity is a structural malalignment of the cervical spine that may present with variety of significant symptomatology for patients. There are clear and substantial negative impacts of cervical spine deformity, including the increased burden of pain, limited mobility and functionality, and interference with patients' ability to work and perform everyday tasks. Primary cervical deformities develop as the result of a multitude of different etiologies, changing the normal mechanics and structure of the cervical region. In particular, degeneration of the cervical spine, inflammatory arthritides and neuromuscular changes are significant players in the development of disease. Additionally, cervical deformities, sometimes iatrogenically, may present secondary to malalignment or correction of the thoracic, lumbar or sacropelvic spine. Previously, classification systems were developed to help quantify disease burden and influence management of thoracic and lumbar spine deformities. Following up on these works and based on the relationship between the cervical and distal spine, Ames-ISSG developed a framework for a standardized tool for characterizing and quantifying cervical spine deformities. When surgical intervention is required to correct a cervical deformity, there are advantages and disadvantages to both anterior and posterior approaches. A stepwise approach may minimize the drawbacks of either an anterior or posterior approach alone, and patients should have a surgical plan tailored specifically to their cervical deformity based upon symptomatic and radiographic indications. This state-of-the-art review is based upon a comprehensive overview of literature seeking to highlight the normal cervical spine, etiologies of cervical deformity, current classification systems, and key surgical techniques.

Positive Outcomes Following Cervical Acceleration-Deceleration (CAD) Injury Using Chiropractic BioPhysics® Methods: A Pre-Auto Injury and Post-Auto Injury Case Series

This series illustrates how rear-end impact motor vehicle collisions (MVCs) alter the cervical spine's alignment and demonstrates therapeutic use of cervical extension traction to improve lordotic alignment and other outcomes. This is a retrospective reporting of 7 adult patients (4 males and 3 females, 28-42 years) treated for cervical hypolordosis. These subjects received Chiropractic BioPhysics® (CBP®) rehabilitation and then were involved in a rear-end MVC. All cases had radiographic assessment that quantified the buckling of the cervical spine, presumably resulting directly from the CAD trauma. After an average of 3 years and 9 months (range: 1-7.6 years) following their initial program of care, the 7 patients sought care for a second time after the MVC. At this time, compared with their previously recorded post-treatment spine radiographs, there was an average 18.7° (range: 7.6-35.4°) reduction in cervical lordosis, a 9.2 mm (range: 3.6-19.8 mm) increase in anterior head translation (AHT), an 11.3° (range: 0.2-19.9°) decrease in the atlas plane line (APL), as well as a 35.7% (range: 22-52%) average neck disability index score (NDI) measured after the MVC. After the crash, a second round of CBP rehabilitation was administered, resulting in an average 15.1° improvement in cervical lordosis, 10.9 mm reduction in AHT, 10.4° increase in APL, and a 23.7% drop in NDI after an average of 35 treatments over 9 weeks. Treatment was universally successful, as an average 80% re-establishment of the lordosis toward its pre-injury state was found. There were no adverse events reported. This case series demonstrates that motor vehicle collisions may alter the alignment of the cervical spine. Rehabilitation of the cervical curve using extension traction improved the patients' initial pre-crash alignments toward their pre-injury alignments and was likely responsible for improvement in the patients' conditions. Clinical trials are needed to confirm these findings.

Using Electrical Stimulation of the Ulnar Nerve Trunk to Predict Postoperative Improvement in Hand Clumsiness in Patients With Cervical Spondylotic Myelopathy

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

To investigate whether the immediate and short-term effects of preoperative electrical peripheral nerve stimulation (ePNS) on performance of the 10-second test could predict the early postoperative outcomes of patients with cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

Previous studies have shown that early clinical improvement in CSM patients may be because of reversal of spinal cord ischemia after spinal cord compression.

MATERIALS AND METHODS

We conducted a 10-second test before surgery, after ePNS, and at discharge (one week after surgery) in 44 patients with CSM who underwent C3-C7 laminoplasty and evaluated their correlations. The effects of the procedures (ePNS or operation) and sides (stimulated or nonstimulated side) for the 10-second test were analyzed using repeated measures analysis of variance. The Pearson correlation coefficient was used to measure the relationship between the 10-second test values according to the method (after ePNS vs. surgery). In addition, the Bland-Altman method was used to evaluate the degree of agreement between the 10-second test obtained after ePNS versus shortly after surgery.

RESULTS

The preoperative 10-second test showed the most improvement immediately after the administration of ePNS, with a gradual decrease for the first 30 minutes after completion. After the initial 30 minutes, performance decreased rapidly, and by 60 minutes performance essentially returned to baseline. The 10-second post-ePNS had a strong positive correlation with the 10-second test in the early postoperative period (at discharge=one week after surgery). These phenomena were observed with the left hand, the side stimulated with ePNS, as well as the right hand, the side not stimulated.

CONCLUSIONS

Early postoperative outcomes after CSM surgery may be predicted by the results of preoperative ePNS.

LEVEL OF EVIDENCE

Level 3.

Distal junctional kyphosis in adult cervical deformity patients: where does it occur?

PURPOSE

To evaluate the impact of the lowest instrumented vertebra (LIV) on Distal Junctional kyphosis (DJK) incidence in adult cervical deformity (ACD) surgery.

METHODS

Prospectively collected data from ACD patients undergoing posterior or anterior-posterior reconstruction at 13 US sites was reviewed up to 2-years postoperatively (n = 140). Data was stratified into five groups by level of LIV: C6-C7, T1-T2, T3-Apex, Apex-T10, and T11-L2. DJK was defined as a kyphotic increase > 10° in Cobb angle from LIV to LIV-1. Analysis included DJK-free survival, covariate-controlled cox regression, and DJK incidence at 1-year follow-up.

RESULTS

25/27 cases of DJK developed within 1-year post-op. In patients with a minimum follow-up of 1-year (n = 102), the incidence of DJK by level of LIV was: C6-7 (3/12, 25.00%), T1-T2 (3/29, 10.34%), T3-Apex (7/41, 17.07%), Apex-T10 (8/11, 72.73%), and T11-L2 (4/8, 50.00%) (p < 0.001). DJK incidence was significantly lower in the T1-T2 LIV group (adjusted residual = -2.13), and significantly higher in the Apex-T10 LIV group (adjusted residual = 3.91). In covariate-controlled regression using the T11-L2 LIV group as reference, LIV selected at the T1-T2 level (HR = 0.054, p = 0.008) or T3-Apex level (HR = 0.081, p = 0.010) was associated with significantly lower risk of DJK. However, there was no difference in DJK risk when LIV was selected at the C6-C7 level (HR = 0.239, p = 0.214).

CONCLUSION

DJK risk is lower when the LIV is at the upper thoracic segment than the lower cervical segment. DJK incidence is highest with LIV level in the lower thoracic or thoracolumbar junction.

Single-Stage Posterior Approach for Multilevel Cervical Ossification of the Posterior Longitudinal Ligament With K-line (-) Using Thick Cervical Pedicle Screw System: A Technical Note and Preliminary Results

STUDY DESIGN

Technical note, retrospective case series.

OBJECTIVE

The optimal surgical strategy for multilevel cervical ossification of the posterior longitudinal ligament (OPLL) with a negative kyphosis line (K-line (-)) remains controversial. We present a novel single-stage posterior approach that converts the K-line from negative to positive in patients with multilevel cervical OPLL, using a posterior thick cervical pedicle screw (CPS) system and report the procedure's outcomes and feasibility.

METHODS

Twelve consecutive patients with multilevel cervical OPLL and K-line (-) underwent single-stage posterior thick CPS fixation, with laminectomy and foraminal decompression. A pre-bent rod was installed to convert the K-line from negative to positive. Radiographic parameters, including the extent and occupying ratio of OPLL and the C2-C7 angle, were examined. CPS accuracy was assessed using computed tomography. The Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores were analyzed. Quality of life was assessed using the Neck Disability Index (NDI). The mean OPLL extent was 5 vertebral body levels, and posterior decompression was performed on 4.2 segments.

RESULTS

The average C2-C7 angle and the occupying ratio of OPLL improved from -9.0° to 14.3° and from 63% to 33%, respectively. The preoperative JOA, VAS, and NDI scores significantly improved from 8.4 to 13.3, from 7.1 to 2.2, and from 21.9 to 9.3, respectively. The K-line was converted from negative to positive in all cases. No severe complications were identified.

CONCLUSION

Single-stage posterior surgery with a thick CPS system may be a reliable and effective treatment for multilevel cervical OPLL and K-line (-).

Operative treatment outcomes for adult cervical deformity: a prospective multicenter assessment with mean 3-year follow-up

OBJECTIVE

Adult cervical deformity (ACD) has high complication rates due to surgical complexity and patient frailty. Very few studies have focused on longer-term outcomes of operative ACD treatment. The objective of this study was to assess minimum 2-year outcomes and complications of ACD surgery.

METHODS

A multicenter, prospective observational study was performed at 13 centers across the United States to evaluate surgical outcomes for ACD. Demographics, complications, radiographic parameters, and patient-reported outcome measures (PROMs; Neck Disability Index, modified Japanese Orthopaedic Association, EuroQol-5D [EQ-5D], and numeric rating scale [NRS] for neck and back pain) were evaluated, and analyses focused on patients with ≥ 2-year follow-up.

RESULTS

Of 169 patients with ACD who were eligible for the study, 102 (60.4%) had a minimum 2-year follow-up (mean 3.4 years, range 2-8.1 years). The mean age at surgery was 62 years (SD 11 years). Surgical approaches included anterior-only (22.8%), posterior-only (39.6%), and combined (37.6%). PROMs significantly improved from baseline to last follow-up, including Neck Disability Index (from 47.3 to 33.0) and modified Japanese Orthopaedic Association score (from 12.0 to 12.8; for patients with baseline score ≤ 14), neck pain NRS (from 6.8 to 3.8), back pain NRS (from 5.5 to 4.8), EQ-5D score (from 0.74 to 0.78), and EQ-5D visual analog scale score (from 59.5 to 66.6) (all p ≤ 0.04). More than half of the patients (n = 58, 56.9%) had at least one complication, with the most common complications including dysphagia, distal junctional kyphosis, instrumentation failure, and cardiopulmonary events. The patients who did not achieve 2-year follow-up (n = 67) were similar to study patients based on baseline demographics, comorbidities, and PROMs. Over the course of follow-up, 23 of the total 169 enrolled patients were reported to have died. Notably, these represent all-cause mortalities during the course of follow-up.

CONCLUSIONS

This multicenter, prospective analysis demonstrates that operative treatment for ACD provides significant improvement of health-related quality of life at a mean 3.4-year follow-up, despite high complication rates and a high rate of all-cause mortality that is reflective of the overall frailty of this patient population. To the authors' knowledge, this study represents the largest and most comprehensive prospective effort to date designed to assess the intermediate-term outcomes and complications of operative treatment for ACD.

Use of a smartphone leveling application to optimize cervical thoracic alignment prior to posterior instrumentation

OBJECTIVE

Posterior cervical decompression and instrumentation (PCDI) is often associated with increase in sagittal balance and loss of lordosis. Here we propose a simple method of surgical positioning utilizing a readily available smartphone application to optimize cervical thoracic alignment in PCDI. The intent of this optimization is to minimize losses in lordosis and increases in sagittal balance.

METHODS

For patients since 2019, the position of the head was adjusted so that the occiput to thoracic spine was aligned and the chin brow angle was parallel to the rails of the surgical table utilizing a leveling smart application (RIDGID Level). Patients before 2019 who were not optimized were compared.

RESULTS

There were 13 patients in the nonoptimized cohort (NOC) and 20 in the optimized cohort (OC). In the NOC, the change in lordosis was -7° (p=0.016) and change in C2-SVA was 7 mm (p<0.001) from preoperative to postoperative values. In the OC, the change in lordosis was 2° (p=0.104) and change in C2-SVA was 2 mm (p=0.592) from preoperative to postoperative values. Between the NOC and OC cohorts, the changes in lordosis and sagittal balance between cohorts were significant (p=0.002 and p=0.001 respectively). There was no significant difference in clinical outcomes as measured by JOA or complication rates.

CONCLUSION

Positioning of the patient in preparation for PCDI can influence post-operative lordosis and sagittal balance. Using the leveling application on the smart phone (RIDGID Level), is a rapid and free alternative for the maintenance of lordosis and sagittal balance during instrumentation in the operating room.

Restoring cervical lordosis by cervical extension traction methods in the treatment of cervical spine disorders: a systematic review of controlled trials

[Purpose] To systematically review the literature on the use of cervical extension traction methods for increasing cervical lordosis in those with hypolordosis and cervical spine disorders. [Methods] Literature searches for controlled clinical trials were performed in Pubmed, PEDro, Cochrane, and ICL databases. Search terms included iterations related to the cervical spine, neck pain and disorders, and extension traction rehabilitation. [Results] Of 1,001 initially located articles, 9 met the inclusion/exclusion criteria. The trials demonstrated increases in radiographically measured lordosis of 12-18°, over 5-15 weeks, after 15-60 treatment sessions. Untreated controls/comparison groups not receiving extension traction showed no increase in cervical lordosis. Several trials demonstrated that both traction and comparison treatment groups experienced immediate pain relief. Traction treatment groups maintained their pain and disability improvements up to 1.5 years later. Comparative groups not receiving lordosis improvement experienced regression of symptoms towards pre-treatment values by 1 years' follow-up. [Conclusion] There are several high-quality controlled clinical trials substantiating that increasing cervical lordosis by extension traction as part of a spinal rehabilitation program reduces pain and disability and improves functional measures, and that these improvements are maintained long-term. Comparative groups who receive multimodal rehabilitation but not extension traction experience temporary relief that regresses after treatment cessation.

Demonstration of central conduction time and neuroplastic changes after cervical lordosis rehabilitation in asymptomatic subjects: a randomized, placebo-controlled trial

A randomized controlled study was conducted to evaluate the effect of rehabilitation of the cervical sagittal configuration on sensorimotor integration and central conduction time in an asymptomatic population. Eighty (32 female) participants with radiographic cervical hypolordosis and anterior head translation posture were randomly assigned to either a control or an experimental group. The experimental group received the Denneroll cervical traction while the control group received a placebo treatment. Interventions were applied 3 × per week for 10 weeks. Outcome measures included radiographic measured anterior head translation distance, cervical lordosis (posterior bodies of C2–C7), central somatosensory conduction time (latency) (N13–N20), and amplitudes of potentials for spinal N13, brainstem P14, parietal N20 and P27, and frontal N30. Outcomes were obtained at: baseline, after 10 weeks of intervention, and at 3 months follow up. After 10 weeks and 3-months, between-group analyses revealed statistically significant differences between the groups for the following measured variables: lordosis C2–C7, anterior head translation, amplitudes of spinal N13, brainstem P14, parietal N20 and P27, frontal N30 potentials (P < 0.001), and conduction time N13–N20 (P = 0.004). Significant correlation between the sagittal alignment and measured variables were found (P < 0.005). These findings indicate restoration of cervical sagittal alignment has a direct influence on the central conduction time in an asymptomatic population.

Factors which predict adverse events following surgery in adults with cervical spinal deformity

AIMS

The aim of this study was to identify the risk factors for adverse events following the surgical correction of cervical spinal deformities in adults.

METHODS

We identified adult patients who underwent corrective cervical spinal surgery between 1 January 2007 and 31 December 2015 from the MarketScan database. The baseline comorbidities and characteristics of the operation were recorded. Adverse events were defined as the development of a complication, an unanticipated deleterious postoperative event, or further surgery. Patients aged < 18 years and those with a previous history of tumour or trauma were excluded from the study.

RESULTS

A total of 13,549 adults in the database underwent primary corrective surgery for a cervical spinal deformity during the study period. A total of 3,785 (27.9%) had a complication within 90 days of the procedure, and 3,893 (28.7%) required further surgery within two years. In multivariate analysis, male sex (odds ratio (OR) 0.90 (95% confidence interval (CI) 0.8 to 0.9); p = 0.019) and a posterior approach (compared with a combined surgical approach, OR 0.66 (95% CI 0.5 to 0.8); p < 0.001) significantly decreased the risk of complications. Osteoporosis (OR 1.41 (95% CI 1.3 to 1.6); p < 0.001), dyspnoea (OR 1.48 (95% CI 1.3 to 1.6); p < 0.001), cerebrovascular accident (OR 1.81 (95% CI 1.6 to 2.0); p < 0.001), a posterior approach (compared with an anterior approach, OR 1.23 (95% CI 1.1 to 1.4); p < 0.001), and the use of bone morphogenic protein (BMP) (OR 1.22 (95% CI 1.1 to 1.4); p = 0.003) significantly increased the risks of 90-day complications. In multivariate regression analysis, preoperative dyspnoea (OR 1.50 (95% CI 1.3 to 1.7); p < 0.001), a posterior approach (compared with an anterior approach, OR 2.80 (95% CI 2.4 to 3.2; p < 0.001), and postoperative dysphagia (OR 2.50 (95% CI 1.8 to 3.4); p < 0.001) were associated with a significantly increased risk of further surgery two years postoperatively. A posterior approach (compared with a combined approach, OR 0.32 (95% CI 0.3 to 0.4); p < 0.001), the use of BMP (OR 0.48 (95% CI 0.4 to 0.5); p < 0.001) were associated with a significantly decreased risk of further surgery at this time.

CONCLUSION

The surgical approach and intraoperative use of BMP strongly influence the risk of further surgery, whereas the comorbidity burden and the characteristics of the operation influence the rates of early complications in adult patients undergoing corrective cervical spinal surgery. These data may aid surgeons in patient selection and surgical planning. Cite this article: Bone Joint J 2021;103-B(4):734-738.

Cortical volume reductions as a sign of secondary cerebral and cerebellar impairment in patients with degenerative cervical myelopathy

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Degenerative cervical myelopathy is the most common cause of chronic impairment of the spinal cord.

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MRI-based anatomical assessment of cerebral and cerebellar areas revealed significant tissue volume reduction in DCM patients compared to healthy controls.

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Disease severity correlated with cerebral and cerebellar atrophy in the primary motor cortex, primary somatosensory cortex and cerebellar areas.

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Chronic injury to the spinal cord seems to have impact on remote anatomical structures in the brain.

This study investigated supra- and infratentorial structural gray and white matter (GM, WM) alterations in patients with degenerative cervical myelopathy (DCM) as an indicator of secondary harm due to chronic cervical cord compression and micro trauma. With MRI-based anatomical assessment and subsequent voxel-based morphometry analyses, pre- and postoperative volume alterations in the primary motor cortex (MI), the primary somatosensory cortex (SI), the supplementary motor area (SMA), and the cerebellum were analyzed in 43 DCM patients and 20 controls. We assessed disease-related symptom severity by the modified Japanese Orthopaedic Association scale (mJOA). The study also explored symptom severity-based brain volume alterations as well as their association with clinical status. Patients had lower mJOA scores (p = .000) and lower GM volume than controls in SI (p = .016) and cerebellar regions (p = .001). Symptom severity-based subgroup analyses revealed volume reductions in almost all investigated GM ROIs (MI: p = .001; CB: p = .040; SMA: p = .007) in patients with severe clinical symptoms as well as atrophy already present in patients with moderate symptom severity. Clinical symptoms in DCM were associated with cortical and cerebellar volume reduction. GM volume alterations may serve as an indicator of both disease severity and ongoing disease progression in DCM, and should be considered in further patient care and treatment monitoring.

Pedicle Subtraction Osteotomy for Deformity Correction in the Upper Cervical Spine: A Technical Note

BACKGROUND

 Kyphosis is the most common deformity of the cervical spine leading to development of severe disabilities. In case of fused kyphosis, surgical treatment can be demanding and often requires multiple-step procedures for adequate correction. We present a technique of single-stage pedicle subtraction osteotomy (PSO) of C3 to treat a patient with fused kyphosis of C2 and C3 causing spinal stenosis with subsequent myelopathy.

METHODS

 A 53-year-old man presented with progressive myelopathy not able to walk with 6/18 points on the modified Japanese Orthopedic Association scale. Horizontal gaze was lost due to cervical kyphosis. Magnetic resonance imaging (MRI) revealed a cervical kyphosis causing stenosis, cord compression, and kinking; computed tomography (CT) showed substantial anterior and posterior fusion of C2 and C3.

RESULTS

 Surgery included decompression via laminectomy of C2 to C6 in combination with PSO of C3 and additional dorsal instrumentation of C2 to C6. Cervical spinal alignment was corrected, as the C2-C4 Cobb angle was reduced from 48.9 to 20.6 degrees. Horizontal gaze was restored. Postoperative MRI demonstrated full decompression of the cord without kinking of the vertebral arteries. No complications were noted. The patient recovered well with restoration of his ability to walk.

CONCLUSION

 Single-stage pedicle subtraction closing wedge osteotomy in the upper cervical spine, although a demanding surgical procedure, is an alternative treatment option in selected cases of fused and severe cervical kyphosis. In contrast to multiple-step approaches, the single-stage procedure could reduce operating time and may thus decrease complications.

Decreased angiogenesis as a possible pathomechanism in cervical degenerative myelopathy

Endogenous immune mediated reactions of inflammation and angiogenesis are components of the spinal cord injury in patients with degenerative cervical myelopathy (DCM). The aim of this study was to identify alteration of certain mediators participating in angiogenetic and inflammatory reactions in patients with DCM. A consecutive series of 42 patients with DCM and indication for surgical decompression were enrolled for the study. 28 DCM patients were included, as CSF samples were taken preoperatively. We enrolled 42 patients requiring surgery for a thoracic abdominal aortic aneurysm (TAAA) as neurologically healthy controls. In 38 TAAA patients, CSF samples were taken prior to surgery and thus included. We evaluated the neurological status of patients and controls prior to surgery including NDI and mJOA. Protein-concentrations of factors with a crucial role in inflammation and angiogenesis were measured in CSF via ELISA testing (pg/ml): Angiopoietin 2, VEGF-A and C, RANTES, IL 1 beta and IL 8. Additionally, evaluated the status of the blood-spinal cord barrier (BSCB) by Reibers´diagnostic in all participants. Groups evidently differed in their neurological status (mJOA: DCM 10.1 ± 3.3, TAAA 17.3 ± 1.2, p < .001; NDI: DCM 47.4 ± 19.7, TAAA 5.3 ± 8.6, p < .001). There were no particular differences in age and gender distribution. However, we detected statistically significant differences in concentrations of mediators between the groups: Angiopoietin 2 (DCM 267.1.4 ± 81.9, TAAA 408.6 ± 177.1, p < .001) and VEGF C (DCM 152.2 ± 96.1, TAAA 222.4 ± 140.3, p = .04). DCM patients presented a mild to moderate BSCB disruption, controls had no signs of impairment. In patients with DCM, we measured decreased concentrations of angiogenic mediators. These results correspond to findings of immune mediated secondary harm in acute spinal cord injury. Reduced angiogenic activity could be a relevant part of the pathogenesis of DCM and secondary harm to the spinal cord.

Cervical spine degenerative disease is an independent risk factor for increased revision rate following total knee arthroplasty

INTRODUCTION

The relationship between cervical degenerative pathology and total knee arthroplasty (TKA) revision rates is not well understood. The aim of the study was to determine whether cervical spine degenerative diseases have a role in complications following TKA within 2 years.

METHODS

Data were collected from the Humana insurance database using the PearlDiver Patient Records Database from 2007-2017. Patients who had a primary TKA were identified using Current Procedural Terminology (CPT) code 27,447, and patients with degenerative cervical disease were identified using CPT and International Classification of Diseases (ICD) codes. Data on patients' demographics, comorbidities and postoperative complications were recorded and analyzed with univariate and multivariate analysis with significance set at p < 0.05. A Kaplan-Meier analysis was conducted to estimate the 1- and 2-year rates of survival free from revision.

RESULTS

A total of 81,873 patients were included in this study. Following multivariate analysis, cervical spine degenerative disease patients were at increased risk of all-cause revision surgery following 1 year (OR: 1.342 95% CI: 1.149-1.569; p < 0.001) and 2 year (OR: 1.338; 95% CI: 1.184-1.512; p < 0.001). At 2 years, patients with cervical spine degenerative disease had a survival rate of 97.7%, while the survival rate was 99.2% among the non-cervical degenerative cohort.

CONCLUSIONS

Based on these results, patients with cervical spine degenerative pathology should be counseled that their spinal pathology may impair outcomes following TKA.

Impact of the Inclusion of C2 in Posterior Cervical Fusions for Cervical Myelopathy on Sagittal Cervical Alignment

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine the impact of including C2 in posterior fusions on radiographic parameters of cervical alignment in cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

Despite the use of posterior instrumentation and arthrodesis after cervical laminectomy, loss of lordosis and the development of kyphosis are prevalent. Inadequate cervical lordosis and other measures of sagittal cervical alignment have been shown to correlate with disability, general health scores, and severity of myelopathy. The role of C2 in the posterior tension band, which maintains sagittal alignment, differs from the subaxial spine, as it is the insertion point for erector spinae muscles that play a critical role in maintaining posture.

PATIENTS AND METHODS

This study compares the radiographic outcomes of sagittal balance between 2 cohorts of patients who underwent posterior cervical decompression and fusion for cervical myelopathy over a 12-year period at a single institution. Demographic and surgical characteristics were collected using the electronic medical record of patients undergoing posterior cervical fusions (PCF) which included the axis [axial fusion (AF)] and those that were subaxial fusions (SAF). Radiographic measurements included preopertaive and postoperative C2-C7 lordosis (CL), C2-C7 sagittal vertical axis (SVA), and T1 slope (T1S).

RESULTS

After review of the electronic medical records, 229 patients were identified as having PCF and decompression for treatment of myelopathy. One hundred sixty-seven patients had AF, whereas 62 had SAF. PCF resulted in loss of CL in both cohorts. Although there was no statistical difference in postoperative CL, there was a significant increase in SVA (P<0.001) and T1S (P<0.001) with AF.

CONCLUSIONS

PCF often result in loss of lordosis. When compared with SAF, inclusion of C2 into the fusion construct may result in worsened sagittal balance, increasing the SVA and T1S.

Patients with degenerative cervical myelopathy have signs of blood spinal cord barrier disruption, and its magnitude correlates with myelopathy severity: a prospective comparative cohort study

PURPOSE

The aim of this study is to detect the presence of blood spinal cord barrier (BSCB) disruption in patients with degenerative cervical myelopathy (DCM).

METHODS

In this prospective non-randomized controlled cohort study, 28 patients with DCM were prospectively included. All patients had indication for neurosurgical decompression. Furthermore, 38 controls with thoracic abdominal aortic aneurysm (TAAA) and indication for surgery were included. All patients underwent neurological examination. Regarding BSCB disruption and intrathecal immunoglobulin (Ig) concentrations, cerebrospinal fluid (CSF) and blood serum were examined for albumin, IgG, IgA and IgM. Quotients (Q) (CSF/serum) were standardized and calculated according to Reibers' diagnostic criteria.

RESULTS

Patients and controls distinguished significantly in their clinical status. AlbuminQ, as expression of BSCB disruption, was significantly increased in the DCM patients compared to the controls. Quotients of IgG and IgA differed significantly between the groups as an expression of intrathecal diffusion. In the subgroup analysis of patients with mild/moderate clinical status of myelopathy and patients with severe clinical status, the disruption of the BSCB was significantly increased with clinical severity. Likewise, IgAQ and IgGQ presented increased quotients related to the clinical severity of myelopathy.

CONCLUSION

In this study, we detected an increased permeability and disruption of the BSCB in DCM patients. The severity of BSCB disruption and the diffusion of Ig are related to the clinical status in our patient cohort. Having documented this particular pathomechanism in patients with DCM, we suggest that this diagnostic tool cloud be an important addition to surgical decision making in the future. These slides can be retrieved under Electronic Supplementary Material.

Perioperative complications with multilevel anterior and posterior cervical decompression and fusion

OBJECTIVE

Cervical spondylotic myelopathy (CSM) is a progressive degenerative pathology that frequently affects older individuals and causes spinal cord compression with symptoms of neck pain, radiculopathy, and weakness. Anterior decompression and fusion is the primary intervention to prevent neurological deterioration; however, in severe cases, circumferential decompression and fusion is necessary. Published data regarding perioperative morbidity associated with these complex operations are scarce. In this study, the authors sought to add to this important body of literature by documenting a large single-surgeon experience of single-session circumferential cervical decompression and fusion.

METHODS

A retrospective analysis was performed to identify intended single-stage anterior-posterior or posterior-anterior-posterior cervical spine decompression and fusion surgeries performed by the primary surgeon (V.C.T.) at Rush University Medical Center between 2009 and 2016. Cases in which true anterior-posterior cervical decompression and fusion was not performed (i.e., those involving anterior-only, posterior-only, or delayed circumferential fusion) were excluded from analysis. Data including standard patient demographic information, comorbidities, previous surgeries, and intraoperative course, along with postoperative outcomes and complications, were collected and analyzed. Perioperative morbidity was recorded during the 90 days following surgery.

RESULTS

Seventy-two patients (29 male and 43 female, mean age 57.6 years) were included in the study. Fourteen patients (19.4%) were active smokers, and 56.9% had hypertension, the most common comorbidity. The most common clinical presentation was neck pain in 57 patients (79.2%). Twenty-three patients (31.9%) had myelopathy, and 32 patients (44.4%) had undergone prior cervical spine surgery. Average blood loss was 613 ml. Injury to the vertebral artery was encountered in 1 patient (1.4%). Recurrent laryngeal nerve palsy was observed in 2 patients (2.8%). Two patients (2.8%) had transient unilateral hand grip weakness. There were no permanent neurological deficits. Dysphagia was encountered in 45 patients (62.5%) postoperatively, with 23 (32%) requiring nasogastric parenteral nutrition and 9 (12.5%) patients ultimately undergoing percutaneous endoscopic gastrostomy (PEG) placement. Nine of the 72 patients required a tracheostomy. The incidence of pneumonia was 6.9% (5 patients) overall, and 2 of these patients were in the tracheostomy group. Superficial wound infections occurred in 4 patients (5.6%). Perioperative death occurred in 1 patient. Reoperation was necessary in 10 patients (13.9%). Major perioperative complications (permanent neurological deficit, vascular injury, tracheostomy, PEG tube, stroke, or death) occurred in 30.6% of patients. The risk of minor perioperative complications (temporary deficit, dysphagia, deep vein thrombosis, pulmonary embolism, urinary tract infection, pneumonia, or wound infection) was 80.6%.

CONCLUSIONS

Single-session anterior-posterior cervical decompression and fusion is an inherently morbid operation required in select patients with cervical spondylotic myelopathy. In this large single-surgeon series, there was a major perioperative complication risk of 30.6% and minor perioperative complication risk of 80.6%. This overall elevated risk for postoperative complications must be carefully considered and discussed with the patient preoperatively. In some situations, shared decision making may lead to the conclusion that a procedure of lesser magnitude may be more appropriate.

The Efficacy of Posterior Cervical Laminectomy for Multilevel Degenerative Cervical Spondylotic Myelopathy in Long Term Period

Study Design:

This was a retrospective analysis.

Background:

Surgical decompression is the gold standard for preventing the progression of neurological deficit in degenerative multilevel cervical spondylotic myelopathy (CSM). The efficacy of posterior laminectomy in the surgical management of CSM has been described in the past, but long-term follow-up data are scanty.

Objective:

The aim of this study is to assess the long-term clinical-radiological outcomes following posterior cervical decompressive laminectomy in multilevel degenerative CSM.

Materials and Methods:

A retrospective analysis of 110 patients with degenerative multilevel CSM who underwent posterior cervical laminectomy alone in a single hospital by a single surgeon from 2009 to 2013 with minimum 5-year follow-up. Pre- and post-operative clinical parameters (visual analog scale [VAS], Nurick and modified Japanese orthopedic association [mJOA]), radiological parameter (Sagittal cervical Cobb's Angle), perioperative complications (time, blood loss, and hospital stay), postoperative complications (infection, C5 palsy, and neurological worsening) were evaluated.

Results:

Totally 110 patients (males – 68 and females – 42) with age varying from 46 to 80 (mean-57) years, and the mean duration of illness was 3 months were evaluated. Mean clinical parameters are VAS (preoperative = 5 ± 1.31, postoperative = 1.49 ± 0.687), Nurick grading (preoperative = 3.23 ± 71, postoperative = 1.924 ± 0.75), and mJOA (preoperative = 6.32 ± 0.87, postoperative = 9.89 ± 1.37). The mean blood loss was 93.95 ± 19.18 ml, and the mean time taken for surgery was 83.65 ± 10.18 min. About 13% (n = 15) patients developed cervical kyphosis and 29% (n = 32) developed changes in cervical spine alignment and 10% (n = 11) developed worsening of neurology at final follow-up. Two patients developed a superficial infection which was managed with antibiotics. Three patients developed C5 palsy which recovered with due time.

Conclusions:

With the proper selection of patients, posterior cervical laminectomy is effective in offering a clinical improvement to patients with degenerative multilevel CSM with a low incidence of clinically significant radiological deterioration.

Predictive model for distal junctional kyphosis after cervical deformity surgery

BACKGROUND CONTEXT

Distal junctional kyphosis (DJK) is a primary concern of surgeons correcting cervical deformity. Identifying patients and procedures at higher risk of developing this condition is paramount in improving patient selection and care.

PURPOSE

The present study aimed to develop a risk index for DJK development in the first year after surgery.

STUDY DESIGN/SETTING

This is a retrospective review of a prospective multicenter cervical deformity database.

PATIENT SAMPLE

Patients over the age of 18 meeting one of the following deformities were included in the study: cervical kyphosis (C2-7 Cobb angle>10°), cervical scoliosis (coronal Cobb angle>10°), positive cervical sagittal imbalance (C2-C7 sagittal vertical axis (SVA)>4 cm or T1-C6>10°), or horizontal gaze impairment (chin-brow vertical angle>25°).

OUTCOME MEASURES

Development of DJK at any time before 1 year.

METHODS

Distal junctional kyphosis was defined by both clinical diagnosis (by enrolling surgeon) and post hoc identification of development of an angle<-10° from the end of fusion construct to the second distal vertebra, as well as a change in this angle by <-10° from baseline. Conditional Inference Decision Trees were used to identify factors predictive of DJK incidence and the cut-off points at which they have an effect. A conditional Variable-Importance table was constructed based on a non-replacement sampling set of 2,000 Conditional Inference Trees. Twelve influencing factors were found; binary logistic regression for each variable at significant cutoffs indicated their effect size.

RESULTS

Statistical analysis included 101 surgical patients (average age: 60.1 years, 58.3% female, body mass index: 30.2) undergoing long cervical deformity correction (mean levels fused: 7.1, osteotomy used: 49.5%, approach: 46.5% posterior, 17.8% anterior, 35.7% combined). In 2 years after surgery, 6% of patients were diagnosed with clinical DJK; however, 23.8% of patients met radiographic definition for DJK. Patients with neurologic symptoms were at risk of DJK (odds ratio [OR]: 3.71, confidence interval [CI]: 0.11-0.63). However, no significant relationship was found between osteoporosis, age, and ambulatory status with DJK incidence. Baseline radiographic malalignments were the most numerous and strong predictors for DJK: (1) C2-T1 tilt>5.33 (OR: 6.94, CI: 2.99-16.14); (2) kyphosis<-50.6° (OR: 5.89, CI: 0.07-0.43); (3) C2-C7 lordosis<-12° (OR: 5.7, CI: 0.08-0.41); (4) T1 slope minus cervical lordosis>36.4 (OR: 5.6, CI: 2.28-13.57); (5) C2-C7 SVA>56.3° (OR: 5.4, CI: 2.20-13.23); and (6) C4_Tilt>56.7 (OR: 5.0, CI: 1.90-13.1). Clinically, combined approaches (OR: 2.67, CI: 1.21-5.89) and usage of Smith-Petersen osteotomy (OR: 2.55, CI: 1.02-6.34) were the most important predictors of DJK.

CONCLUSIONS

In a surgical cohort of patients with cervical deformity, we found a 23.8% incidence of DJK. Different procedures and patient malalignment predicted incidence of DJK up to 1 year. Preoperative T1 slope-cervical lordosis, cervical kyphosis, SVA, and cervical lordosis all strongly predicted DJK at specific cut-off points. Knowledge of these factors will potentially help direct future study and strategy aimed at minimizing this potentially dramatic occurrence.

Correlation analysis of sagittal alignment and skeletal muscle mass in patients with spinal degenerative disease

We investigated how skeletal muscle mass (SMM) affects spinal sagittal balance (radiographic parameters) in symptomatic spinal patients. The first purpose of this study was to evaluate the body composition and the spinal sagittal alignment in symptomatic spinal patients. The second purpose of this study was to compare whether the body composition and the spinal sagittal alignment is different in patients with cervical spine disease and lumbar spine disease. We retrospectively evaluated 313 patients who were hospitalized for surgery to treat spinal degenerative disease, who were divided into cervical and lumbar spine disease groups. All patients underwent full-length standing whole-spine radiography and bioimpedance analysis (BIA) before surgery. We used standard measurements to assess the sagittal vertical axis (SVA), cervical lordosis (CL; C2–C7), lumbar lordosis (LL; T12–S1), thoracic kyphosis (TK; T5–12), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). We also analyzed radiological and body composition parameters, patient characteristics, and the correlation between SMM and each sagittal parameters. In the overall cohort, the mean age at the time of operation was 66.5 ± 15.3 years and 59.2% of the patients were men. The correlation coefficients (r) between SMM and PT were negative weak correlation (r = −0.343, P < 0.001). The correlation with SMM for other LL, PI, SS, and SVA was statistically significant, but the correlation was none. In addition, our results also suggested strong correlations (r > 0.5) between LL and SS (r = 0.744), between LL and SVA (r = −0.589), between PT and SS (r = −0.580), and LL and PT (r = −0.506). Fifty-seven patients (18.2%, cervical group) had cervical spine disease and 256 patients (81.8%, lumbar group) had lumbar spine disease. No significant differences in age, height, body weight, and body mass index were observed between the two groups. The SMM of patients with cervical and lumbar spine disease also did not differ significantly. In the lumbar group, correlations were found between SMM and PT (r = −0.288, P < 0.001), between SMM and LL (r = 0.179, P < 0.01), and between SMM and SS (r = 0.170, P < 0.01), while only PT (r = −0.480, P < 0.001) was negatively correlated with SMM in the cervical group. This analysis indicated that PT is the sagittal parameter most closely related to SMM in patients with the spinal degenerative disease. The SMM might be one of the important factors that influenced the posterior inclination of the pelvis in symptomatic spinal patients, especially in cervical spine disease.

Development of the Portuguese Version of the Modified Japanese Orthopaedic Association Score: Cross-Cultural Adaptation, Reliability, Validity, and Responsiveness

BACKGROUND

Spondylotic cervical myelopathy (SCM) is a common cause of spinal-related disability in elderly patients. The assessment of this disability is a challenging task and depends on the subjective evaluation of the investigator. As a widespread-used scale, the modified version of the Japanese Orthopaedic Association score (mJOA) should be translated and culturally adapted in the Brazilian Portuguese language (i.e., mJOA-Br) to provide its clinical and research use. This study aimed to perform translation, transcultural adaptation, and validation of the mJOA into Brazilian Portuguese.

METHODS

Following the transcultural adaptation model described by Guillemin et al., the scale as translated into Brazilian Portuguese and back-translated to English. Afterwards, questionnaires were applied in consecutive patients with SCM and compared with a control group (without SCM). The final scale was compared with the Brazilian version of Neck Disability Index for validation.

RESULTS

Sixty patients were submitted to the translated version of mJOA. There was a strong correlation between mJOA-Br scores and Neck Disability Index scores to evaluate SCM symptoms (R = -0.75).

CONCLUSIONS

mJOA-Br was considered a valid and reliable tool to evaluate patients with SCM.

Impact of Cervical Spine Deformity on Preoperative Disease Severity and Postoperative Outcomes Following Fusion Surgery for Degenerative Cervical Myelopathy: Sub-analysis of AOSpine North America and International Studies

STUDY DESIGN

Sub-analysis of the prospective AOSpine CSM North America and International studies.

OBJECTIVE

The aim of this study was to investigate the impact of cervical spine deformity on pre- and postoperative outcomes in fusion surgeries for degenerative cervical myelopathy.

SUMMARY OF BACKGROUND DATA

The associations between cervical alignment and patient outcomes have been reported but are not well established in a myelopathy cohort. The impact of deformity correction in this population also needs to be elucidated.

METHODS

A total of 757 patients were enrolled in two prospective international multicenter AOSpine studies. Among those who underwent anterior or posterior fusion surgeries, pre- and 1-year postoperative upright neutral lateral radiographs of cervical spine were investigated to measure C2-7 Cobb angle and C2-7 sagittal vertical axis (SVA). Patient outcome measures included the modified Japanese Orthopedic Association score for myelopathy severity, Neck Disability Index (NDI), and Short-form 36 (SF-36). These scores were compared between patients with and without cervical deformity, which was defined as C2-7 Cobb >10° kyphosis and/or SVA >40 mm.

RESULTS

A total of 178 patients were included with complete pre- and postoperative radiographs. SVA significantly increased postoperatively (27.4 vs. 30.7 mm, P = 0.004). All outcome measurement showed significant improvements above minimal clinically important differences. 23.6% of the patients had cervical deformity preoperatively; preoperative deformity was associated with worse preoperative NDI scores (45.7 vs. 38.9, P = 0.04). Postoperatively, those with deformity exhibited significantly lower SF-36 physical component scores (37.2 vs. 41.4, P = 0.048). However, when focusing on the preoperatively deformed cohort, we did not find any significant differences in the postoperative outcome scores between those with and without residual deformity.

CONCLUSION

There was a significant association between cervical deformity and both preoperative disease severity and postoperative outcomes; however, no impact of deformity correction was shown.

LEVEL OF EVIDENCE

2.

Difference in Spinal Sagittal Alignment and Health-Related Quality of Life between Males and Females with Cervical Deformity

Study Design

Large cohort study.

Purpose

To clarify spinal sagittal alignment and health-related quality of life (HRQOL) according to sex in volunteers aged >50 years with cervical deformity (CD).

Overview of Literature

Adult spinal deformities, especially those associated with lumbosacral lesions, are more frequent in females; however, CD is observed to a greater extent in males.

Methods

We divided 656 volunteers (263 males, 393 females; age, 50–89 years [mean, 73 years]) as follows: males with CD (CDM; 82 patients); males without CD (NCDM, 181); females with CD (CDF, 36); and females without CD (NCDF, 357). CD was defined as C2–7 sagittal vertical axis (SVA) ≥40 mm. We measured pelvic tilt (PT), pelvic incidence minus lumbar lordosis (PI−LL), thoracic kyphosis, T1 slope, cervical lordosis, C7 SVA, and C2–7 SVA. HRQOL was evaluated using EuroQOL five dimensions questionnaire (EQ-5D).

Results

In CDM, NCDM, CDF, and NCDF groups, the respective parameters were as follows: PT: 15°, 14°, 26°, and 21°; PI−LL: 7°, 5°, 16°, and 10°; C2–7 SVA: 49, 24, 46, and 20 mm; C7 SVA: 61, 40, 75, and 47 mm; and EQ-5D: 0.82, 0.88, 0.78, and 0.81. PT and PI−LL were significantly greater in the CDF group than in the NCDF group (p<0.05) but were not significantly different between CDM and NCDM groups. The CDF group already showed deterioration of spinopelvic alignment, although it was maintained in the CDM group. EQ-5D in showed significantly greater deterioration the CDM group than in the NCDM group; deterioration of lumbopelvic parameters had less influence in males (p<0.05).

Conclusions

Sagittal spinal deformity may have different mechanisms in males and females. The deterioration of spinal sagittal alignment in males may originate from the cervical spine, and CD may be associated with HRQOL.

Surgical planning for cervical deformity based on a 3D model

The treatment of fixed cervical deformity is complex, but the principles guiding its correction remain the same as in deformity of other spinal regions, with the goal of deformity correction that results in a solid fusion with adequate decompression of the neural elements. In these challenging cases, osteotomies are necessary to mobilize the rigid spine and to obtain the desired correction, but they can be associated with increased risk of complications. Therefore, careful preoperative planning and a complete understanding of the anatomic variations allow patient-tailored approaches with and case specific techniques for the optimal and safe treatment of a variety of complex cervical deformities. We present a case report with a complex spinal deformity where a 3D model was used for surgical strategy that allowed us to “simulate” the osteotomies and get a better correction of the cervical deformity.

A Clinical Practice Guideline for the Management of Degenerative Cervical Myelopathy: Introduction, Rationale, and Scope

Degenerative cervical myelopathy (DCM) is a progressive spine disease and the most common cause of spinal cord dysfunction in adults worldwide. Patients with DCM may present with common signs and symptoms of neurological dysfunction, such as paresthesia, abnormal gait, decreased hand dexterity, hyperreflexia, increased tone, and sensory dysfunction. Clinicians across several specialties encounter patients with DCM, including primary care physicians, rehabilitation specialists, therapists, rheumatologists, neurologists, and spinal surgeons. Currently, there are no guidelines that outline how to best manage patients with mild (defined as a modified Japanese Orthopedic Association (mJOA) score of 15-17), moderate (mJOA = 12-14), or severe (mJOA ≤ 11) myelopathy, or nonmyelopathic patients with evidence of cord compression. This guideline provides evidence-based recommendations to specify appropriate treatment strategies for these populations. The intent of our recommendations is to (1) help identify patients at high risk of neurological deterioration, (2) define the role of nonoperative and operative management in each patient population, and (3) determine which patients are most likely to benefit from surgical intervention. The ultimate goal of these guidelines is to improve outcomes and reduce morbidity in patients with DCM by promoting standardization of care and encouraging clinicians to make evidence-informed decisions.

Characterizing Adult Cervical Deformity and Disability Based on Existing Cervical and Adult Deformity Classification Schemes at Presentation and Following Correction

BACKGROUND

Adult cervical deformity (ACD) classifications have not been implemented in a prospective ACD population and in conjunction with adult spinal deformity (ASD) classifications.

OBJECTIVE

To characterize cervical deformity type and malalignment with 2 classifications (Ames-ACD and Schwab-ASD).

METHODS

Retrospective review of a prospective multicenter ACD database. Inclusion: patients ≥18 yr with pre- and postoperative radiographs. Patients were classified with Ames-ACD and Schwab-ASD schemes. Ames-ACD descriptors (C = cervical, CT = cervicothoracic, T = thoracic, S = coronal, CVJ = craniovertebral) and alignment modifiers (cervical sagittal vertical axis [cSVA], T1 slope minus cervical lordosis [TS-CL], modified Japanese Ortphopaedic Association [mJOA] score, horizontal gaze) were assigned. Schwab-ASD curve type stratification and modifier grades were also designated. Deformity and alignment group distributions were compared with Pearson χ2/ANOVA.

RESULTS

Ames-ACD descriptors in 84 patients: C = 49 (58.3%), CT = 20 (23.8%), T = 9 (10.7%), S = 6 (7.1%). cSVA modifier grades differed in C, CT, and T deformities (P &lt; .019). In C, TS-CL grade prevalence differed (P = .031). Among Ames-ACD modifiers, high (1+2) cSVA grades differed across deformities (C = 47.7%, CT = 89.5%, T = 77.8%, S = 50.0%, P = .013). Schwab-ASD curve type and presence (n = 74, T = 2, L = 6, D = 2) differed significantly in S deformities (P &lt; .001). Higher Schwab-ASD pelvic incidence minus lumbar lordosis grades were less likely in Ames-ACD CT deformities (P = .027). Higher pelvic tilt grades were greater in high (1+2) cSVA (71.4% vs 36.0%, P = .015) and high (2+3) mJOA (24.0% vs 38.1%, P = .021) scores. Postoperatively, C and CT deformities had a trend toward lower cSVA grades, but only C deformities differed in TS-CL grade prevalence (0 = 31.3%, 1 = 12.2%, 2 = 56.1%, P = .007).

CONCLUSION

Cervical deformities displayed higher TS-CL grades and different cSVA grade distributions. Preoperative associations with global alignment modifiers and Ames-ACD descriptors were observed, though only cervical modifiers showed postoperative differences.

A novel technique to correct kyphosis in cervical myelopathy due to continuous-type ossification of the posterior longitudinal ligament

OBJECTIVE

Although posterior decompressive surgery is widely used to treat patients with cervical myelopathy and multilevel ossification of the posterior longitudinal ligament (OPLL), a poor outcome is anticipated if the sagittal alignment is kyphotic (or K-line negative). Accordingly, it is mandatory to perform anterior decompression and fusion in patients with cervical kyphosis. However, it can be difficult to perform anterior surgery because of the high risk of complications. This present report proposes a novel “greenstick fracture technique” to change the K-line from negative to positive in patients with cervical myelopathy, OPLL, and kyphotic deformity.

METHODS

Four patients with cervical myelopathy, continuous-type OPLL, and kyphotic sagittal alignment (who were K-line negative) were indicated for surgery. Posterior laminectomy and lateral mass screw insertions using a posterior approach were performed, followed by anterior surgery. Multilevel discectomy and thinning of the OPLL mass by bur drilling was performed, then an intentional greenstick fracture at each disc level was made to convert the cervical K-line from negative to positive. Finally, posterior instrumentation using a rod was carried out to maintain cervical lordosis.

RESULTS

MRI showed complete decompression of the cord by posterior migration in all cases, which had been caused by cervical lordosis. Restoration of neurological defects was confirmed at the 1-year follow-up assessment. No specific complications were identified that were associated with this technique.

CONCLUSIONS

A greenstick fracture technique may be effective and safe when applied to patients with cervical myelopathy, continuous-type OPLL, and kyphotic deformity (K-line negative). However, further studies with more cases will be required to reveal its generalizability and safety.

Relief of Lumbar Symptoms After Cervical Decompression in Patients with Tandem Spinal Stenosis Presenting with Primarily Lumbar Pain

Objective: Tandem cervical and lumbar spinal stenosis (TSS) is classically described as intermittent claudication, gait disturbance, and clinical findings of mixed myelopathy and polyradiculopathy. Rarely, patients can present with TSS manifesting in isolated lumbar pain. Several reports have demonstrated improved lumbar back pain and radiculopathy after decompressive cervical spine procedures. We present six patients with dramatic resolution of lumbar spine related symptoms after decompression of the cervical spinal cord despite presenting solely with lower back complaints.

Methods: Clinical records of the senior author (F.A.S.) gathered from April 2006 to March 2013 were retrospectively reviewed identifying six patients presenting solely with lumbar symptoms and diagnosed with TSS based on history and physical examination.

Results: Six patients with a mean age of 55 (range 39 to 60) presented with solely lower back symptoms and clinical findings suspicious for TSS. Mean follow-up time for all patients was 12 months (range three to 27 months, median 11.5 months). Three patients underwent a cervical procedure as the principal operation, while the remainder had the lumbar spine decompressed initially. All patients that underwent a cervical procedure initially experienced a dramatic decrease or complete resolution of their preoperative lower back pain and radiculopathy (mean preoperative VAS of 6.7 vs. 3.7 postoperative). The remainder of patients with persistent lumbar symptoms resolved after a subsequent cervical operation.

Conclusion: Patients presenting with lumbar symptoms out of proportion to imaging require further investigation. We highlight the resolution of lumbar symptoms after a cervical procedure in a select group of patients presenting with lone lower back complaints. In patients presenting with symptoms disproportionate to lumbar imaging, treatment of cervical pathology may provide robust long-term relief of the initial lumbar-related presentation. 

Degenerative cervical myelopathy

Cervical myelopathy is the most common cause of acquired spinal cord compromise. The concept of degenerative cervical myelopathy (DCM), defined as symptomatic myelopathy associated with degenerative arthropathic changes in the spine axis, is being introduced. Given its progressive nature, treatment options have to be chosen in a timely manner. Surgical options include anterior discectomy and fusion (ACDF), anterior corpectomy and fusion (ACCF), arthroplasty (in highly select cases), posterior laminectomy with/without fusion, and laminoplasty. Indications for each should be carefully considered in individual patients. Riluzole, a sodium-glutamate antagonist, is a promising option to optimize neurologic outcomes post-surgery and is being examined in the CSM-Protect Randomized Controlled Trial. Preoperative risk assessment is mandatory for prognostication. Sagittal alignment is known to play an important role to optimize surgical outcome. Guidelines for optimal management of DCM are in process. In principle, all but the mildest cases of DCM should be offered surgery for optimal outcome.

A retrospective study to reveal the effect of surgical correction of cervical kyphosis on thoraco-lumbo-pelvic sagittal alignment

PURPOSE

Recent studies suggest that cervical lordosis is influenced by thoracic kyphosis and that T1 slope is a key factor determining cervical sagittal alignment. However, no previous study has investigated the influence of cervical kyphosis correction on the remaining spinopelvic balance. The purpose of this study is to assess the effect of surgical correction of cervical kyphosis on thoraco-lumbo-pelvic alignment.

METHODS

Fifty-five patients who underwent ≥2 level cervical fusions for cervical radiculopathy or myelopathy were included. All patients had regional or global cervical kyphosis, which was surgically corrected into lordosis. Radiographic measurements were made using whole spine standing lateral radigraphs pre- and postoperatively to analyze various sagittal parameters. The visual analogue scale (VAS) for neck pain and the neck disability index (NDI) were calculated. The paired t test was used to compare pre- and post-operative radiographic measures and functional scores. Correlations between changes in cervical sagittal parameters and those of other sagittal parameters were analyzed by Pearson's correlation method.

RESULTS

Preoperative kyphosis (11.4° ± 8.3°) was corrected into lordosis (-9.3° ± 8.1°). The average fusion levels were 3.3 ± 1.0. With increasing C2-C7 lordosis after surgery (from -3.4° ± 10.0° to -15° ± 7.9°), C0-C2 lordosis decreased significantly (from -34.6° ± 8.2° to -27.7° ± 8.0°) (P < 0.001). Thoracic kyphosis (from 24.8 ± 13.9° to 33.5 ± 11.9°) and T1 slope (from 12.8° ± 7.9° to 20.4° ± 5.2°) significantly increased after surgery (P < 0.001). However, other parameters did not significantly change (P > 0.05). Neck pain VAS and NDI scores (31.8 ± 16.2) significantly improved (P < 0.001). The degree of increasing C2-C7 lordosis by surgical correction was negatively correlated with changes in both thoracic kyphosis and T1 slope (P < 0.01).

CONCLUSIONS

Surgical correction of cervical kyphosis affects T1 slope and thoracic kyphosis, but not lumbo-pelvic alignment. These results indicate that the compensatory mechanisms to minimize positive sagittal malalignment of the head may occur mainly in the thoracic, and not in the lumbosacral spine.

Prospective Multicenter Assessment of Early Complication Rates Associated With Adult Cervical Deformity Surgery in 78 Patients

BACKGROUND

Acute kidney injury (AKI) is a serious postoperative complication.

OBJECTIVE

To determine whether AKI in patients after craniotomy is associated with heightened 30-day mortality.

METHODS

We performed a 2-center, retrospective cohort study of 1656 craniotomy patients who received critical care between 1998 and 2011. The exposure of interest was AKI defined as meeting RIFLE (Risk, Injury, Failure, Loss of Kidney Function, and End-stage Kidney Disease) class risk, injury, and failure criteria, and the primary outcome was 30-day mortality. Adjusted odds ratios were estimated by multivariable logistic regression models with inclusion of covariate terms thought to plausibly interact with both AKI and mortality. Additionally, mortality in craniotomy patients with AKI was analyzed with a risk-adjusted Cox proportional hazards regression model and propensity score matching as a sensitivity analysis.

RESULTS

The incidences of RIFLE class risk, injury, and failure were 5.7%, 2.9%, and 1.3%, respectively. The odds of 30-day mortality in patients with RIFLE class risk, injury, or failure fully adjusted were 2.79 (95% confidence interval “CI”, 1.76-4.42), 7.65 (95% CI, 4.16-14.07), and 14.41 (95% CI, 5.51-37.64), respectively. Patients with AKI experienced a significantly higher risk of death during follow-up; hazard ratio, 1.82 (95% CI, 1.34-2.46), 3.37 (95% CI, 2.36-4.81), and 5.06 (95% CI, 2.99-8.58), respectively, fully adjusted. In a cohort of propensity score-matched patients, RIFLE class remained a significant predictor of 30-day mortality.

The Influence of Age and Sex on Cervical Spinal Alignment Among Volunteers Aged Over 50

STUDY DESIGN

Large cohort study of volunteers aged over 50.

OBJECTIVE

To investigate influence of age and sex on cervical sagittal alignment among volunteers aged over 50.

SUMMARY OF BACKGROUND DATA

Few large-scale studies have described normative values in cervical spine alignment regarding age and sex among volunteers aged over 50.

METHODS

The study cohort included 656 volunteers aged 50 to 89 years. Pelvic tilt, sacral slope, pelvic incidence, lumbar lordosis, pelvic incidence-lumbar lordosis, thoracic kyphosis, T1 slope (T1S), cervical lordosis (CL), C7 sagittal vertical axis (C7 SVA), C2-C7 SVA, and T1S-CL were measured using whole spine and pelvic radiographs taken in the standing position. Health-related quality of life was assessed using the EuroQOL (EQ-5D) standardized instrument for measurement of health outcome and Oswestry Disability Index.

RESULTS

There were 36 subjects aged 50 to 59 years, 174 aged 60 to 69 years, 311 aged 70 to 79 years, and 135 aged 80 to 89 years. Average T1S for each decade was 32°, 31°, 33°, and 36° for males, and 28°, 29°, 32°, and 37° for females, respectively. Average C2-C7 SVA was 25, 28, 34, and 35 mm for males, and 20, 21, 22, and 28 mm for females, respectively. C2-C7 SVA 40 mm or more, T1S 40° or more, and T1S-CL 20° or more pertaining to EQ-5D were significantly worse in other cases.

CONCLUSION

C2-C7 SVA was significantly greater in males among all age groups, particularly among those with C2-C7 SVA of 40 mm or more [males, 69% (82/118) vs. females, 33% (36/118)]. Sagittal parameters of cervical spine were significantly worse in males than females. C2-C7 SVA, T1S, and T1S-CL negatively influenced EQ-5D. These results help to explain the greater prevalence of cervical spondylotic myelopathy among elderly males.

LEVEL OF EVIDENCE

3.